TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2385 SUBJECT: GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER DATE: 03/09/17 10:23:25 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, A. Krylov, V. Kornilov, G. Borisov, D. Kuvshinov, A. Belinski, I. Chilingarian, M. Kuznetsov, S. Potanin, V. Vitrischak, G. Antipov Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow report: MASTER system (280mm, http://observ.pereplet.ru) with new AP16E CCD camera (~7 square degrees) was pointed automatically after receiving HETE 2849 alert (120 seconds after GRB time). But due to weather and technical conditions the first direct image of the error box area was obtained 43 minutes after GRB. The weather conditions were poor (almost full Moon + cirrus clouds), so the limiting magnitude of the first image was about 13.5 (unfiltered instrumental magnitude). After that we received about 100 images of the 7 square degrees (2.65x2.65 deg) area around the center of error box with limiting magnitude about 16.0. We stopped the data processing after receiving cancellation report from HETE, but after receiving GCN2383 we made the data reduction of 2 images (the 1st and the best). There was no OT detected up to 13.5, 43 minutes after GRB time in a 1 degree circular error box. There was no OT detected up to 16.0, 2h41m after GRB time in the same error box. Reduced FITS images (dark,bias substracted, flat normalized) are available at http://www.sai.msu.su/~aleks/observ/ These are our first results with new large CCD, so we still have no pipeline to reduct them. But if anybody likes to process these data (about 7 Gigabytes including calibration frames) we can provide an access to them. Submit your requests to lipunov@sai.msu.ru This message may be cited.